1. Field of Invention
The invention generally relates to detection and alignment of light outside the visible region of the spectrum. More specifically, the invention relates to a laminated card and the use of the laminated card for near-visible light detection and beam alignment.
2. Description of Related Art
A near-visible light detection apparatus enables a user to determine whether a near-visible light source is functioning. The detection apparatus can also determine the location of a near-visible light beam, and align a plurality of beams.
The prior art includes laminated detector cards from Quantex, now Lumitek International, Inc., that have active phosphor sensor regions. Examples of the prior art detector cards include the Lumitek infrared sensor cards (e.g., Q-11, Q-16, Q-32 and Q-42 cards), and the Lumitek ultraviolet sensor cards (e.g., U-21-R and U-21-T cards). The detector cards provide an instantly visible pattern for determining spatial information about the beam, such as beam location and approximate beam size for near-visible light beams. In addition, the high sensitivity of the detectors provides users of various near-visible light sources and components (e.g. emitting diodes, optical fibers, etc.) with a tool for determining the presence or absence of near-visible light.
The sensor regions extend out towards the edge of the detector cards, but are separated from the card edges by a laminated edge width. In the prior art, the required minimum laminate edge width from the edge of the detector card to the sensor region is approximately five millimeters.
Because the phosphor sensor is separated from the edge of the prior art detector card by approximately five millimeters, the user is not able to place the sensor in a position to detect near-visible light on some impinged surfaces. Where the near-visible light of interest is present only within less than five millimeters of an obstructing structure, the prior art cards cannot detect the light. The obstructing structure prevents the user from manipulating the prior art card into a detection position because the phosphor sensor is approximately five millimeters from the card edge. For example, in a tightly spaced beam manipulation system, the near-visible light beam is reflected from a first to a second surface. The prior art detector cards are unable to determine where the beam is impinging the first surface if the impingement occurs within less than five millimeters of an edge of a surface that prevents placement of the card above or on the other side of the surface.
When confronted with such limited access equipment, users of prior art detector cards were forced to trim off the laminated edge to place the sensor at the location needed for beam detection. After removal of the laminate material, the detector card phosphor sensor is exposed to ambient conditions and degrades from exposure to air and humidity in a few months. A new card must then be used for further detection needs.
There is a need for a durable apparatus for detecting near-visible light in limited access conditions. This need is not addressed by detector cards or other apparatus with protective coverings disclosed in the background art.
One aspect of the invention provides an apparatus for detecting light having a near-visible frequency. The near-visible light can be infrared light having wavelengths approximately between 0.8 micrometers and 1.7 micrometers, or ultraviolet light having wavelengths approximately between 250 nanometers and 500 nanometers. The apparatus includes a sensor and a covering.
The sensor includes a near-visible to visible light conversion phosphor. The phosphor defines an active area of the apparatus. The phosphor extends to within about a first distance of a flush portion of a first edge.
The covering has a thickness. The covering is adapted to cover the sensor and to substantially protect the phosphor from degradation. The first distance corresponds approximately to the thickness of the covering.